1. Field of the Invention
The present invention relates in general to the field of electronic input devices and, more particularly, to a stylus that operates as a pointer to interact with information presented on an electronic display, and/or to read an image, absent contact with the display or label and having one or more buttons that can be programmed to perform differing input functions.
2. Description of the Related Art
The following descriptions and examples are not admitted to be prior art by virtue of their inclusion within this section.
Personal computers utilize various mechanisms in which to input information. For example, most personal computers have a port onto which a mouse can be connected. A typical mouse has one or more buttons and a scroll wheel. By moving the mouse, a cursor can be moved across an electronic display using various graphics driver software. Once the cursor is placed at the appropriate position, a button can be clicked to select a portion of the displayed subject matter, such as hypertext or an icon. Typical mice have wires that run from a mouse to port on the personal computer, and such mice are generally referred to as tethered input devices.
With the increased market for portable computers, most tethered input devices have been displaced by a joystick built into the keyboard. The joystick can be arranged somewhere upon, for example, a keyboard of the computer, or personal digital assistant (PDA), henceforth generically referred to as portable devices. Such portable devices, however, still require a keyboard and a physical (i.e., wired) connection between the input device and the portable device's input port. An even more portable device absent a keyboard, or the constraints of a mechanically connected joystick, is a tablet portable device.
Tablet devices, or tablet PCs, generally do not use a QWERTY-type keyboard. Instead, a tablet PC utilizes a stylus electronic input device. The stylus communicates with a digitizing surface (i.e., the surface of the tablet electronic display). Since most conventional styluses are shaped like a pen, the typical application is to enter handwritten material into memory of the tablet. For example, an operator will grasp the stylus housing similar to the manner in which a writing instrument is grasped, and the operator will activate a pressure sensitive tip of the stylus by forcing the tip against the digitizer tablet surface. By moving the stylus similar to the way in which a person might sign his or her name on a sheet of paper, the signature would appear on the tablet and be stored in memory.
Although pen-type styluses can be un-tethered, or wireless, most typical styluses require contact with the writing surface. The purpose of contacting the writing surface is two-fold. First, the surface of the tablet might be pressure sensitive such that when the tip contacts the surface, the position of the pen can be ascertained relative to the X and Y coordinates of the tablet. Second, even if the surface is not pressure sensitive, many conventional surfaces utilize radio frequency (RF) waves that are transmitted in close proximity to the tablet upper surface. The surface waves are detected by an antenna or coil placed in the pen. Before the coil is activated to resonate with the imparted RF wave, contact with the tip upon the surface is necessary to detect a pen-down position, in readiness for the handwriting operation. Examples of pen-type styluses used as a writing instrument requiring contact or contact-activation against a tablet surface are described in U.S. Pat. Nos. 6,577,299; 5,565,632; 5,004,871; 4,814,552; and 4,786,765 herein incorporated by reference.
While pen-type styluses represent one type of application for a tablet portable device, another equally viable application is not for the purpose of storing handwritten information but as a pointer. Instead of contacting the surface of a tablet PC to discern the pen position or to activate the pen, it would be desirable to introduce a completely contactless and wireless pointer-type stylus. The desired stylus need not be limited to the entry of handwritten information, but could operate as a remote pointer to select a portion of graphical information displayed on the tablet without physically contacting the tip of the stylus upon the tablet surface. This would allow a user to possibly stand apart and away from the table PC when giving, for example, a demonstration to an audience viewing the screen without blocking or disrupting their angle of sight. Therefore, the desired application is that of a pointer and not necessarily a pen. By implementing improved detection technology, the desired, contactless pointer-type stylus can be operated with other pointers concurrently and, desirably, to implement other contactless technology such as image scanning and so forth.